1. Field of the Invention
The present invention relates to filters, and in particular, to a liquid filter vessel which provides for easy replacement of the associated filter bag, without contaminating the fluid remaining in the housing.
2. Description of the Relevant Art
Many different filters are in use today in industry. A major concern with the industrial type filter is the ease in which the filter elements can be replaced, since it requires shut-down of the production facility in order to provide this type of maintenance. Many elaborate arrangements are utilized today to make the time consuming job of changing filters acceptable. One approach to simplifying this task is disclosed in U.S. Pat. No. 3,640,392 issued to E. A. Smith et al on Feb. 8, 1972. The Smith et al disclosure overcame the problems known in the prior art, by eliminating the need for disconnecting couplings, flexible hoses, or other types of means for manually disconnecting the liquid inlet line, in order to open the top of the filter vessel. The apparatus disclosed therein provides for a permanent plumbing connection for the pressurized liquid being filtered and does not interfere with the easy opening of the vessel for inspection, replacement of the filter bag and cleaning. The vessel is provided with a cover connected by a unique hinge, contains a basket supported filter bag for filtering the liquid under pressure that enters the mouth of the bag through an inlet in the cover and is discharged through an outlet in the bottom of the vessel. The hinge is provided with a liquid inlet passage which communicates with a liquid supply plumbing connection that is permanent and need not be disturbed when the cover is opened or closed. An annular seal is provided by the rim of the filter basket disposed on the annular wall of the body of the vessel, so that when the cover is closed and clamped, leakage of the pressurized liquid is prevented above the bag, as well as from the vessel itself. The plumbing required to provide for a pressurized liquid into the cover arrangement as disclosed, requires a movable plumbing joint which has a tendency to wear with time, and thereby, permits the pressurized fluid to leak out of the connection. The filter basket requires a unique configuration and utilizes a pair of "O-rings" to provide the liquid type seal in order to prevent leakage between the cover and the vessel housing.
Another type of filter utilized to filter water in swimming pools includes a filter vessel and a rigid, porously fabricated filter basket, which is adapted to receive a filter bag therein. The basket or support member provides a cushioning effect for the filter bag, and prevents the filter bag from coming into contact with the inner tank. The filter basket construction is comprised of a plurality of circumferentially arranged, longitudinally extending fibrous tubes positioned relative to each other, so as to form a cylinder, and fibers bonded on the inside and outside diameters of the cylinders. This filter system is designed for use in relatively low pressure systems, and makes no provision for dispersing the incoming liquid, so that it encompasses the entire surface of the filter bag.
The present invention overcomes the shortcomings found in the known art, by providing a filter vessel which is fabricated of non-metallic parts, is capable of being used under relatively high pressures, and is ideally suited for industrial usage where contamination of the liquids being filtered is of major importance, as well as, the amount of down time required to change the filter element.